On the BSC HEPI L4C input bank there are two filters, one calibrates the raw signal to nm (Cal) and the second contains the sensor symmetrization feature around at 1hz (Sym.)

On the BSC-ISI HEPI L4C, there is only a Cal filter but this also contains the resonance notch.  Attached is the foton comparison, they are close but not exactly the same.  I'm waiting for confirmation from MIT but I think these should be the same.  Along the same lines I'm correcting the BSC-ISI HEPI L4Cto Cart matrix which I think too should be the same as the BSC-HEPI L4C to Cart matrix.

The BSC-ISI HEPI L4C filters should be the same as the BSC-HEPI L4Cs.